The present invention relates to a substrate stage to be used for an XY stage or a large-scale printing apparatus; and more particularly, the invention relates to a large-scale stage in which rails are connected.
Since granite is easily worked on to ensure plane precision and has small thermal strain and large raw stones are obtained, it is used for substrate stages in the XY stage, a large-scale printing apparatus, a three-dimensional inspection apparatus or the like.
Recently, substrates are getting larger, so that if the substrate stage is made larger to meet the large-scale substrate, the stage becomes so large that it cannot be transported on roads.
Therefore, there is a trial period in which small-area tables and short rails are made of raw stones of granite, and are transported to an installation place; and a large-scale substrate stage is set by assembling them at a place where the substrate stage is actually used.
However, when auxiliary mounting tables are attached to a main mounting table and the individually prepared rails are connected each other, there is a problem in that a step is formed at a joined portion of the rails or horizontalness of the rails cannot be ensured, so that substrates cannot be transferred at a high speed.
As technical documents describing large-scale substrate stages, there are the following publications, for example, JPA H07-311375 and JPA 2005-114882.